Question: Solve for $z$ : $-21 = 0.07z$ $z =\,$
Solution: Divide both sides by $0.07$ : ${\dfrac{\color{black}{-21}}{0.07}} = {\dfrac{\color{black}{0.07z}}{0.07}} $ To simplify, remember that when the signs are the same, the quotient is positive. When the signs are different, the quotient is negative. $-300= \dfrac{\cancel{0.07}z}{\cancel{0.07}}$ $z = -300$